Does the Roborock S8 MaxV Ultra actually wash its own mop?

Yes. The RockDock Ultra uses internal water tanks (clean water in, dirty water out) and a brush roller inside the dock to scrub the mop pads after each run. After scrubbing, the dock dries the pads with warm air to prevent mildew. The mop arrives at each cleaning run clean and damp — not soiled from the previous run.

How often do you need to refill the water tank?

In a 1,600 square foot home with approximately 800 square feet of hard floor, the clean water tank required refilling every 4 to 5 days of daily mopping. The dirty water tank required emptying at the same interval. The exact frequency depends on floor area and mopping coverage.

Does the S8 MaxV Ultra avoid carpets when mopping?

Yes. The mop pad physically lifts 20mm when the robot transitions to carpet, preventing carpet wetting. This is supplemented by no-go zone mapping — you can designate carpet areas as mop-free zones. In practice, the automatic lift handles most transitions reliably.

How does it compare to the Roborock S8+ (without the RockDock Ultra)?

The S8+ and S8 MaxV Ultra use the same cleaning hardware. The difference is entirely in the dock: the S8+ has a self-emptying dock with no mop washing. The S8 MaxV Ultra's RockDock Ultra adds mop washing, mop drying, and auto water refill. If you want mopping that stays truly hands-free between tank refills, the RockDock Ultra is required.

Roborock S8 MaxV Ultra Review: The Most Automated Robot Vacuum Mop

The Roborock S8 MaxV Ultra sits at the top of Roborock's lineup by automating the one task most robot vacuum mops still leave to the owner: washing the mop itself. Over four months of daily runs in a 1,600 square foot home with two cats and hard floors, the RockDock Ultra auto-emptied the dustbin, scrubbed and dried the mop pads, and refilled its own water tank every four to five days. Dual rubber brush rolls kept pet hair from tangling despite spring shedding season, and the 10000Pa suction motor, among the strongest in the consumer category, cleared embedded cat hair from medium-pile carpet in a single pass. LiDAR navigation held up equally well in daylight and total darkness, a real advantage over camera-based systems. This review covers what changes when a dock handles mopping start to finish, and where the S8 MaxV Ultra still falls short, namely pet waste avoidance for dog owners.

What the RockDock Ultra Changes

Robot vacuums with self-emptying docks are not new. What the S8 MaxV Ultra's RockDock Ultra adds is the complete automation of the mop — self-washing, self-drying, and self-refilling. In practice, this means the mopping function becomes as hands-free as the vacuuming function, for the first time in a consumer robot vacuum.

Without a dock that washes the mop, a combined vacuum mop robot requires the owner to manually rinse the mop pads after each run. If that step is skipped, the robot mops subsequent floors with soiled pads — redepositing the previous run's dirt onto new surfaces. This is the fundamental limitation of every mopping robot without a washing dock.

The RockDock Ultra addresses this problem directly. After each cleaning run, the dock:

Draws the mop pads back into the dock
Scrubs the pads with an internal brush roller using clean water
Drains the dirty water into the dirty water tank
Dries the pads with warm air to prevent mildew

The result: the robot begins each cleaning run with clean, damp mop pads. In four months of daily use, the mop pads required manual replacement twice (they wear with regular use) but never required manual rinsing.

Dual Rubber Brush Rolls

The S8 MaxV Ultra uses two rubber brush rolls instead of the single rubber or bristle roll found in most competitors. The effect on pet hair pickup is significant — in four months with two cats shedding heavily during spring, the brush rolls required cutting only once. By comparison, a bristle brush robot tested previously in the same household required cutting every 3 to 4 runs.

The dual brush design also improves coverage — the two counter-rotating rolls move debris more effectively into the suction path than a single roll. On carpet edges (where single-brush robots often leave debris lines), the dual rolls cleared debris on the first pass.

10000Pa Suction

At 10000Pa, the S8 MaxV Ultra has among the highest suction of any consumer robot vacuum. On medium carpet with embedded cat hair, the difference compared to 2000Pa to 3000Pa models is clearly visible — hair that required two to three passes with a lower-suction robot was cleared in one pass.

The practical question is whether 10000Pa is necessary. For hardwood floors and low carpet: no. 2500Pa to 3000Pa is adequate. For medium carpet with pet hair: yes, the additional suction produces meaningfully better results. For high-pile carpet: no robot vacuum at any suction level fully replaces a traditional upright vacuum for embedded debris.

In the test home with 800 square feet of medium-pile carpet and two cats, max suction mode (10000Pa) produced noticeably cleaner carpet than the same Roborock at 2700Pa (the Q5+ tested previously).

LiDAR (Light Detection and Ranging) uses a spinning laser to map the room by measuring return time of laser pulses. Unlike camera navigation, LiDAR works in complete darkness and is unaffected by reflective surfaces. The S8 MaxV Ultra navigated the test home in both full light and complete darkness with identical accuracy.

The LiDAR system produces a detailed floor plan map that persists between runs and updates automatically as furniture is rearranged. Room labeling, no-go zones, and room-specific cleaning commands all operate through this map. In four months of daily use, the map required no manual correction.

Mopping Performance

Sonic mopping (the mop pad vibrates at 4000 cycles per minute) is more effective than drag-only mopping for removing light residue from hardwood and tile. In the test home, the S8 MaxV Ultra's mopping eliminated the need for manual mopping on hardwood in the kitchen and hallway for the duration of the test — with the qualifier that no heavy spills occurred during this period. Light spills that were allowed to dry before the next cleaning cycle required one manual mopping session during the test.

For deep cleaning (removing wax buildup, cleaning tile grout, removing dried-on residue) no robot vacuum mopping system is adequate. The S8 MaxV Ultra's mopping is correct for daily maintenance, not deep cleaning.

Noise

In standard mode: approximately 60 dB. In max suction mode: approximately 70 dB. The RockDock Ultra's mop washing cycle runs for approximately 3 to 4 minutes after the cleaning run and is audible at approximately 55 dB — significantly quieter than the cleaning run itself.

Who Should Buy the S8 MaxV Ultra

Buy the S8 MaxV Ultra if: you have significant hard floor area that benefits from daily mopping; you have cats or short-hair dogs with no accident history; and you want the most complete floor cleaning automation available without daily intervention.

Consider the Roomba j7+ instead if: you have dogs with any history of indoor accidents. Pet waste avoidance is the one capability the S8 MaxV Ultra lacks and the j7+ provides. The vacuum-only j7+ plus a separate manual mop is safer for dog households than the mopping S8 MaxV Ultra without waste avoidance.

Consider the Roborock Q7+ instead if: you want Roborock quality at a lower price and do not need mopping. The Q7+ offers LiDAR, 4200Pa, and self-emptying at approximately 40% of the S8 MaxV Ultra's price.